Chapter 3

Question 1

Deductive Reasoning

Answer 1

Spelling out whatever conclusion follows logically from your premises, without reference to any external information. Not directly concerned with truth: it is simply concerned with validity, which means the question of whether a particular conclusion inevitably follows from its premises.

Question 2

Deductive Proof

Answer 2

Demonstrating that a particular conclusion logically follows from certain premises, and that this conclusion must be true if these premises are true. A matter of certainty.

Question 3

Truth-Preserving

Answer 3

When used correctly, deductive reasoning is guaranteed to preserve the truth of its premises in its conclusion (just so long as they’re true in the first place).

Question 4

Valid Reasoning

Answer 4

Correctly applying deductive reasoning in drawing out the logical conclusion of your premises.

Question 5

Invalid Reasoning

Answer 5

Incorrectly applying deductive reasoning, so that your conclusion does not logically follow from your premises.

Question 6

Unwarranted

Answer 6

A conclusion that is not supported by the argument

Question 7

Necessary Condition

Answer 7

Must be met if something is to be true, but cannot by itself guarantee the truth of that thing.

Question 8

Sufficient Condition

Answer 8

One that, if met, does guarantee the truth of something.

Question 9

Logic

Answer 9

The study of the principles distinguishing correct from incorrect reasoning.

Question 10

2 Types of Valid & Invalid Reasoning

Answer 10

1. Affirming the antecedent versus affirming the consequent. 2. Denying the consequent versus denying the antecedent.

Question 11

Affirming the Antecedent

Answer 11

A valid form of argument in which, because one thing is said always to follow from another, the truth of the first guarantees the second is also true.

Question 12

Affirming the Antecedent

Answer 12

Premise 1: If A, Then B Premise 2: A Conclusion: Therefore, B

Question 13

Formal Fallacy

Answer 13

An invalid form of argument representing an error in logic, meaning that arguments in this form cannot be relied on to arrive at valid conclusions.

Question 14

Affirming the Consequent

Answer 14

An invalid argument which mistakenly assumes that, when one thing always follows from another, the truth of the second also guarantees the first.

Question 15

Affirming the Consequent

Answer 15

Premise 1: If A, Then B Premise 2: B Conclusion: Therefore, A

Question 16

Denying the Consequent

Answer 16

A valid form of argument in which, because one thing is said always to follow from another, the fact that the second isn’t true also guarantees the first isn’t true.

Question 17

Denying the Consequent

Answer 17

Premise 1: If A, Then B Premise 2: Not B Conclusion: Therefore, not A

Question 18

Denying the Antecedent

Answer 18

An invalid argument which mistakenly assumes that, when one thing always follows from another, the fact that the first isn’t true also guarantees the second isn’t true

Question 19

Denying the Antecedent

Answer 19

Premise 1: If A, Then B Premise 2: Not A Conclusion: Therefore, not B

Question 20

Sound

Answer 20

A deductive argument that is both valid and has true premises, meaning its conclusion must also be true.

Question 21

Unsound

Answer 21

An argument that does not meet the standard of soundness, either because it is invalid or because one or more of its premises is untrue, or both.